Due to their small size, low cost and easy deployment, the nodes of the network are usually called motes. Motes are small, compact and autonomous devices destined to become ubiquitous. WSN is a technology with an enormous potential that can be used in a high number of heterogeneous applications of interest to society such as environmental monitoring, traffic control, structural monitoring of bridges and buildings, tracking of people and objects, assisted living, etc.The software that runs on the motes plays a fundamental role in the development of WSNs. It controls the mote operation, implements the network protocols and manages the hardware power consumption.

Various specific operating systems and programming languages have been proposed to facilitate and speed up the development of new applications.

Currently, the most important and widely adopted operating systems for WSN are TinyOS, Contiki and Mantis. The main goals of all of them are to provide a robust and reliable operation and to maintain the mote in the deepest low power mode compatible with the requirements needed at that moment. Low power operation extends the battery lifetime of the motes and it is probably the most important requirement in this type of systems.A WSN can be considered as an embedded system with severe constraints in terms of memory, computational capacity and power consumption. Traditionally, the development of software for embedded systems with very limited resources has been based on event-driven programming models.

TinyOS follows the event-driven model and achieves efficient low power consumption operation Batimastat and low memory footprint by means of a very simple execution model, similar to the way the hardware works. Contiki is the second operating system being taken into account in this analysis. Contiki, together with TinyOS, are nowadays the most important operating systems for WSN. Both of them support IPv6 in their communications stacks, a key feature for an increasing number of companies and research Drug_discovery institutions that are pursuing a seamless connection of WSNs to Internet.

Contiki can also be considered an event-driven operating system, but it incorporates 1|]# programming abstractions to manage the synchronization of concurrent tasks that facilitate the programming of high level sequences of actions. Finally, unlike the first two cases, Mantis is an example of multithreading operating system. The main features of Mantis are the integration of a multithreading scheduler and the programming abstractions that deal with concurrent threads.The aim of this article is to analyze and compare the low-level current consumption of the mote during the execution of an application running on different operating systems.